Internal combustion engine gasoline injection system

ABSTRACT

The invention relates to a gasoline injection system for an internal combustion engine. A control stop for a shuttle-type metering pump is responsive to a cam follower movable by a diaphragm. The diaphragm is in turn responsive to the pressure drop across the engine intake throttle. An airflow control device is carried in the intake, upstream of the throttle. The control device is operable by an element sensitive to engine temperature to reduce the pressure drop and thereby increase fuel supply at low temperatures. A cam track engaged by the cam follower is energizable during engine starting to further increase the fuel supply.

United States Patent Channing [54] INTERNAL COMBUSTION ENGINE GASOLINEINJECTION SYSTEM [72] Inventor: Derek Channing, Farmington, Mich.

[73] Assignee: Joseph Lucas (Industries) Limited, Birmingham, England[58] FieldofSearch ..l23/1l9, 139.11, 139.11 A, 123/139.17, 139.18,140.3, 179 A, 179L [561 References Cited UNITED STATES PATENTS 2,965,08912/1960 Holley, Jr ..123/l79 L 1 May 23, 1972 2,965,092 12/1960 Claire,Jr. ..l23/l39.l 1 A 2,984,232 5/1961 Arndt et al ..l23/140.3

Primary Examiner-Laurence M. Goodridge Attorney-Holman & Stern ABSTRACTThe invention relates to a gasoline injection system for an internalcombustion engine. A control stop for a shuttle-type metering pump isresponsive to a cam follower movable by a diaphragm. The diaphragm is inturn responsive to the pressure drop across the engine intake throttle.An airflow control device is carried in the intake, upstream of thethrottle. The control device is operable by an element sensitive toengine temperature to reduce the pressure drop and thereby increase fuelsupply at low temperatures. A cam track engaged by the cam follower isenergizable during engine starting to further increase the fuel supply.

1 Claim, 1 Drawing Figure PATENTEDMAY23 m2 3,664,319

INVENTOR MZQW AT RNEYS INTERNAL COMBUSTION ENGINE GASOLINE INJECTIONSYSTEM BACKGROUND OF THE INVENTION This invention relates to aninternalcombustion engine petrol injection system and has as an objectto provide such a system in a convenient form.

SUMMARY OF THE INVENTION A system in accordance with the inventionincludes a temperature sensing element which is sensitive to thetemperature of the engine, an airflow control device actuable by thetemperature sensing element to restrict airflow upstream of the throttleof the engine when the engine is cold, means actuable by the temperaturesensing element to open the throttle from its normal slow runningposition when the engine is cold and a fuel control device forcontrolling the quantity of fuel supplied to the engine, said fuelcontrol device including a control element sensitive to the airpressures on opposite sides of the throttle and arranged to decreasefuel flow as the pressure difference across the throttle increases, saidairflow control device serving to reduce the pressure difference whenthe engine is cold.

In addition, the fuel control device may include means actuable underthe control of the temperature sensing device to increase the fuel flowduring starting of the engine.

BRIEF DESCRIPTION OF THE DRAWINGS An example of the invention isillustrated in the accompanying drawing in which the sole FIGURE is adiagrammatic view, partly in elevation and partly in cross-section.

The system illustrated incorporates a metering pump for a gasolineinjection system. The pump 10 is of known type having an adjustable stop11 displaceable by a control device 12. The device 12 includes a body13, a piston-like member 14 slidable within the body 13, and engaging atits respective ends the stop 11 and a cam follower 15. The cam follower15 comprises a pair of arms 16 supporting a roller 17 and pivotallymounted on a diaphragm assembly 18. The diaphragm assembly 18 defineswithin the body 13 a pair of chambers 19, 20, with sealing means 21being interposed between a part 22 of the diaphragm assembly 18 and anadjacent portion of the body 13. The cam follower roller 17 engages acam track 23 mounted on a pivot 24 in the body 13. The cam track 23 isrotatable about the pivot 24 by means of a lever 25 actuable by asolenoid 26. The cam track 23 is biased clockwise as seen in thedrawing, towards an adjustable limit screw 50 by a spring 27. A terminal26a of the solenoid 26 is connected to a terminal of a starter solenoid(not shown), for the engine.

An engine air intake 28 has adjacent its upstream end 29 an airflowcontrol device in the form of a disc 30 mounted within the bore of theintake 28 upon a pivot 31 which is spaced both from the axis of the boreand the axis of the disc 30. An arm 32 is mounted on the pivot 31 and iscoupled thereto by a light torsion spring 33, whereby the disc 30 may bemoved independently of the arm 32. A lever 34 is pivotally mountedexternally of the intake 28. A bi-metallic coil 35 is arranged to beheated by the exhaust system of the engine and has one end anchored tothe intake 28. The other end of the coil 35 engages the lever 34. Oneend of lever 34 is connected by a link 36 to the arm 32.

The other end of lever 34 is connected by a link 37 to a cam 38, mountedexternally of the intake 28 about a pivot 39. A throttle 40, downstreamof the disc30 is rotatable about a pivot 41 by a lever 42. The lever 42has a pair of adjustable abutments 43, 44 which respectively coact witha stop 45 and with the cam 38. The arrangement is such that, when theengine is cold, the cam 38 operates to open the throttle slightly fromits normal slow running position as determined by the stop 45.

A microswitch 46, connected in series with the solenoid 26 coacts withthe cam 38 so that when the engine is cold, the

switch 46 is closed to engage the solenoid 26. A air of passages 47,48respectively extend between the chambers 19,20 and the bore of the inlet28 upstream and downstream of the throttle 40. In use, during coldstarting, the lever 34 is in the position shown and cam 38 holds switch46 on. The solenoid 26 is thus energized while the starter is energized,rotating the cam track 23 counter-clockwise about the pivot 24 to allowextra fuel to be supplied to the engine. The throttle 40 is heldslightly open by the cam 38. The disc 30 moves under the influence ofairflow through the intake 28 to a position dependent on the magnitudeof the airflow and on the spring 33. The airflow is restricted by boththe disc 30 and throttle 40, instead of by the throttle alone, as isusual. The diaphragm assembly 18 is responsive only to the pressure dropacross the throttle 40, instead of the total pressure drop. The camfollower is thus moved to a lesser extent in a direction to reduce thefuel supply to the engine, and overfuelling results.

As the engine becomes warm, the lever 34 is rotated clockwise and thedisc 30 has less effect in the airflow. The pressure drop across thethrottle thus increases, progressively reducing overfuelling with risein temperature.

During warm starting, above the temperature at which the switch 46operates, solenoid 26 is not energized, and over fuelling is dependentonly on any reduction in thepressure drop across the throttle 40, asdescribed.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is:

1. An internal combustion engine gasoline injection system in which theengine is provided with an air supply passage and a throttle in the airsupply passage, the system including a bimetal coil sensitive to thetemperature of the engine, a disk constituting an air flow controldevice, pivot means mounting the disk within the air supply passageadjacent the upstream end of the air supply for pivotal movement aboutan axis which is spaced from the axis of the disk and the longitudinalaxis of the air supply passage, an arm, a torsion spring coupling thearm to the pivoting means whereby the disk may be moved independently ofthe arm, means attaching one end of the bi-metal coil to the air supplypassage, a lever pivotally mounted externally of the air supply passage,the other end of the bi-metal coil engaging the lever, means connectingone end of the lever to the-arm, a cam pivotally mounted externally ofthe air supply passage, means connecting the other end of the lever tothe cam, said throttle being located downstream of the disk, a pivotabout which the throttle is rotatable, a second lever for rotating thethrottle, an adjustable abutment for each end of the second lever, astop with which one of the adjustable abutments coacts, the otheradjustable abutment coacting with the cam so that when the engine iscold, the cam functions to open the throttle slightly from its normalslow running position as determined by the stop, a fuel control devicefor controlling the quantity of fuel supplied to the engine, said fuelcontrol device including a body, a diaphragm providing a pair ofchambers in the body, passage means providing communication between theair supply passage upstream of the throttle and one of the chambers,second passage means providing communication between the air supplypassage downstream of the throttle and the other of the chambers, a camtrack pivotally mounted in the body, a cam follower engaging the camtrack and being movable relative thereto by the diaphragm, ashuttle-type metering pump, a control stop for the metering pump, meansfor transmitting the position of the cam follower to the control stop, asolenoid, means operably connecting the solenoid to the cam track tomove the cam track about its pivotal mounting, and a microswitchconnected in series to the solenoid and cooperable with the cam so thatwhen the engine is cold, the microswitch is closed to engage thesolenoid to energize the solenoid to rotate the cam track and allowextra fuel to be supplied to the engine.

1. An internal combustion engine gasoline injection system in which theengine is provided with an air supply passage and a throttle in the airsupply passage, the system including a bimetal coil sensitive to thetemperature of the engine, a disk constituting an air flow controldevice, pivot means mounting the disk within the air supply passageadjacent the upstream end of the air supply for pivotal movement aboutan axis which is spaced from the axis of the disk and the longitudinalaxis of the air supply passage, an arm, a torsion spring coupling thearm to the pivoting means whereby the disk may be moved independently ofthe arm, means attaching one end of the bi-metal coil to the air supplypassage, a lever pivotally mounted externally of the air supply passage,the other end of the bi-metal coil engaging the lever, means connectingone end of the lever to the arm, a cam pivotally mounted externally ofthe air supply passage, means connecting the other end of the lever tothe cam, said throttle being located downstream of the disk, a pivotabout which the throttle is rotatable, a second lever for rotating thethrottle, an adjustable abutment for each end of the second lever, astop with which one of the adjustable abutments coacts, the otheradjustable abutment coacting with the cam so that when the engine iscold, the cam functions to open the throttle slightly From its normalslow running position as determined by the stop, a fuel control devicefor controlling the quantity of fuel supplied to the engine, said fuelcontrol device including a body, a diaphragm providing a pair ofchambers in the body, passage means providing communication between theair supply passage upstream of the throttle and one of the chambers,second passage means providing communication between the air supplypassage downstream of the throttle and the other of the chambers, a camtrack pivotally mounted in the body, a cam follower engaging the camtrack and being movable relative thereto by the diaphragm, ashuttle-type metering pump, a control stop for the metering pump, meansfor transmitting the position of the cam follower to the control stop, asolenoid, means operably connecting the solenoid to the cam track tomove the cam track about its pivotal mounting, and a microswitchconnected in series to the solenoid and cooperable with the cam so thatwhen the engine is cold, the microswitch is closed to engage thesolenoid to energize the solenoid to rotate the cam track and allowextra fuel to be supplied to the engine.